This invention relates to an improved process for the preparation of fibers from spinning dopes and more particularly to the process of extruding the dope from an orifice through a layer of inert gas into a coagulating bath to form fibers.
The prior art U.S. Pat. No. 3,767,756 to Blades teaches a dry jet wet spinning process wherein a dope is extruded from orifices as filaments which are then passed through a layer of inert gas into a quench bath and through a spin tube along with a portion of the quench liquid from the bath. The filaments are separated from the liquid and wound upon a bobbin. The spinning technology disclosed by Blades requires that the spinneret face be separated from the quench bath by a layer of gas the thickness of which must be controlled by controlling the level of the quench bath. Coupled with this requirement is the need to control the speed of the quench liquid with respect to filament speed to regulate the tension profile of the yarn during coagulation to provide a uniform product of high strength.
An object of this invention is to control the speed of the quench liquid surrounding the filaments in a gas gap spinning process while providing self-regulating level control for the quench bath.